Low-loss circuit apparatus



Patented Aug. 15, 1939 UNITED STATES PATENT OFFICE LOW-LOSS CIRCUIT APPARATUS Harry Tuniek, Rye, N. Y., assignor to Radio Corporation of America, al corporation of Dela- Waffe 9 Claims.

This application is a division of my co-pending application Serial No. 26,749, led June 15, 1935, entitled Low loss circuits.

My present invention relates to improved low loss circuit apparatus. It has as its main object the provision of an improved arrangement of a vacuum tube or vacuum tubes and their associated low loss circuits for emciently producing and/or otherwise dealing with waves of very short wave lengths. Figures 1 and 2, which correspond to Figures 9 and 10 of my copending application, illustrate preferred forms of my present invention, wherein one or more vacuum tubes are mounted within concentric resonant low loss circuits.

In the single vacuum tube arrangement of Figure 1, the vacuum tube 990 is mounted within the quarter wave length cylinder 992, as shown. The cylinder 992 is grounded at its bottom `end and the grid 994 of the Vacuum tube 9110 is connected to the outer surface of cylinder 902, as shown. The pair of cylinders 992 and 930 both form one tuned circuit. The plate circuit of the vacuum tube, which consists of a coil and condenser combination 99S, is provided with a tuning knob 998 which protrudes through the cover, not shown, of the oven 912. The oven is provided with a th-ermostat 9141, a heater 916 and a battery 918 for rough temperature control.

Fine temperature control is provided within the inner cylinder 902 by means of battery or other source of potential 929, heating resistor 922 and thermostat 924. Output energy is taken from the coil 926 and ied to any suitable load circuit, such as an antenna, 928. The outer concentric cylinder 939 may be omitted, in which case the entire oven 912 should be made of metal or should be provided with metal walls facing the low loss circuit forming the grid circuit of the oscillation generator.

The push-pull arrangement of the system of Figure 1 is shown in Figure 2. The oven |999 is provided with the heaters 1002, |994, |009, |008 energized by a source of potential |919, under control of the thermostat |912. The vacuum tubes |014 and |916 are supported on the insulating supports |018, 1020 and are provided with a common plate or output circuit |922. The power supply leads |024 are brought in at the electrical center of the frequency controlling tube |026, as is also the plate condenser shaft and knob |021. The inner cylindrical tube |026 is supported upon the outer concentric cylinder |028 by means of the insulators |030. The outer (Cl. Z-36) concentric cylinder, in turn, is supported within the oven |900 by means of insulators |632, |034. The laments of the vacuum tubes, as shown, are provided with chokes |040, |042 which permit the laments to` assume proper high frequency potentials. The grids of the vacuum tubes are tapped to the outer surface of the frequency controlling cylinder |028 at suitable tapping points 105D, |052 through the blocking condensers |954, |956. Grid bias is obtained through chokes |058, |069 and plate potential is obtained through chokes |1362 and |064, which may be shunted by resistors |966, |968, if desired.

It should be understood that the term ground used in this specification is not limited to actual earth, but includes any point or surface of relatively xed alternating current potential.

Having thus described my invention, what I claim is:

l. The combination with a tuned circuit in the form of a concentric line having an cuter conductor and a coaxial hollow inner conductor, of a multi-electrode electron discharge device located within said inner conductor, a connection from one electrode of said device to the outer surface of said inner conductor, and a connection from another electrode of said device to n another point on one of said conduct-ors of said line.

2. The combination with a tuned circuit in the form of a concentric line having an outer conductor and a coaxial hollow inner conductor connected together at one of their adjacent ends, of an electron discharge device within said inner conductor, said` device having a cathode and a grid, a connection from said grid to a point on the outer surface of said inner conductor, and a connection from said cathode to the inner surface of said inner conductor.

3. The combination with a tuned circuit in the form of a concentric line having an outer conductor and a coaxial hollow inner conductor connected together at one oi their adjacent ends, of an electron discharge device within said inner conductor, said device having a cathode, a grid, and an anode, a connection from said grid to a point on the outer surface of said inner conductor, a connection from said cathode to one of said conductors, and a tuned circuit of lumped reactance also located within said inner conductor and connected between said anode and a source of polarizing potential.

4. The combination with a tuned circuit comprising both a hollow conductor devoid of concentrated reactance and a surrounding outer hollow conducting shell coupled to said hollow conductor to form therewith a high frequency circuit, and having a connection from said outer shell to a point of relatively iixed alternating current potential, of a multi-electrode vacuum tube device having input electrodes and being located within said hollow conductor, said input electrodes being connected to said tuned circuit.

5. The combination with a tuned circuit in the form of a concentric line having an outer conductor and a coaxial hollow inner conductor, of a pair of push-pull connected electron discharge devices located within the interior of said inner conductor, each of said devices having a cathode, an anode, and a grid, connections from said grids to diierent points on the outer surface of said inner conductor, a connection between said anodes including a tuned circuit of concentrated reactances also located within said inner conductor, means located externally of said concentric line for heating said cathodes and for supplying polarizing potentials to said anodes, and a utilization circuit coupled to said last tuned circuit.

6. The combination with a tuned circuit in the form of a concentric line having an outer conductor and a coaxial hollow inner conductor, of a pair of push-pull connected electron discharge devices located within the interior of said inner conductor, each of said devices having a cathode, an anode, and a grid, connections from said grids to different points on the outer surface of said inner conductor symmetrically disposed with respect to the center thereof, a connection between said anodes including a tuned circuit of concentrated reactances also located within said inner conductor, means located externally of said concentric line for heating said cathodes and for supplying polarizing potentials to said anodes, and a utilization circuit coupled to said last tuned circuit.

7. The combination with a tuned circuit in the form of a concentric line having an outer conductor and a coaxial hollow inner conductor, of a pair of push-pull connected electron discharge devices located Within the interior of said inner conductor, each of said devices having a cathode, an anode, and a grid, connections from said grids to different points on the outer surface of said inner conductor symmetrically disposed with respect to the center thereof, a connection between said anodes including a tuned circuit of concentrated reactances, means located externally of said concentric line for heating said cathodes and for supplying polarizing potentials to said anodes, and a utilization circuit coupled to said last tuned circuit.

8. The combination with a tuned circuit comprising both a hollow conductor devoid of concentrated reactance and a surrounding outer hollow conducting shell, of a pair of multi-electrode vacuum tubes located within said hollow conductor, each of said devices having a grid electrode coupled to the outer surface of said hollow conductor, whereby said tuned circuit constitutes the input circuits for said Vacuum tubes.

9. The combination with a tuned circuit comprising both a hollow conductor devoid of concentrated reactance and a surrounding outer hollow conducting shell, and having a connection from said outer shell to a point of relatively xed alternating current potential, of a multielectrode vacuum tube located Within said hollow conductor and having certain of its electrodes connected to said tuned circuit, whereby said tuned circuit constitutes the input circuit for said vacuum tube.

HARRY TUNICK. 

